Method for joining crosswisely extending reinforcing bars

ABSTRACT

Method for elevating and joining crosswisely extending reinforcing bars and supporting them in a position raised above the deck of the casting mold in a spacing member having an inverted generally U-shaped body and rod engaging recesses.

United States Patent [1 1 [111 3,789,474

Skold Feb. 5, 1974 METHOD FOR JOINING CROSSWISELY [56] References Cited EXTENDING REINFORCING BARS UNITED STATES PATENTS I [76] Invent Mats F lk k ld, Ba k ag n 3,200,488 8/1965 Johansson 29 212 R Hagersten, Sweden 3,461,536 8/1969 Skold 29/212 R [22] Filed: Feb. 28, 1972 Pnmary ExammerThomas H. Eager pp 229,702 Attorney, Agent, or Firm-Eric Y. Munson et a].

[30] Foreign Application Priority Data [57] ABSTRACT Mar. 2, 1971 Sweden 26l8/7l Method f elevating and joining crosswisely extending reinforcing bars and supporting them in a position U-S. Cl- R, R, raised above the deck of the casting mold in a pacing [51] Int. Cl B23p 17/00 member having an inverted generally U shaped body [58] R,2l2 R,2l2 D,211R,

Field of Search29/ 155 and rod engaging recesses.

2 Claims, 10 Drawing Figures Patented Feb. 5 19 74; 3,789,474

3 Sheets-Sheet 2 Patented Feb. 5, 1974 5 Sheets-Sheet METHOD FOR JOINING CROSSWISELY EXTENDING REINFORCING BARS BACKGROUND OF THE INVENTION The primary object of the invention is to provide an improved method of applying to the crosswisely extending bars a spacer clip as shown in copending application Ser. No. 3,765 filed Jan. 19, 1970 now US. Pat. No. 3,694,988, and in a continuation application filed concurrently herewith Ser. No. 229,703 filed Feb. 28, 1972.

The tool described in said aforesaid US. Pat. No. 3,461,536 was designed primarily for the application of a spacer clip as shown in said patent and for reinforcing bars of relatively light weight and small cross section.

An improved tool, as well as an improved method is desirable, which lends itself for lifting and tying together bars of substantially heavier weight and having larger and varying cross sections, as well as to lighter weight bars of smaller cross section. Furthermore, modern day casting methods often call for the bars being tied together suspended above the deck of the mold when the tool should not be placed on the floor itself of the casting mold and when the bars are not to be further elevated.

SUMMARY OF THE INVENTION The method according to the invention contemplates the use of an elongated vertically extending tool comprising a longitudinal channel or magazine for retaining a plurality of superimposed spacer clips which are placed over two crosswisely extending reinforcing bars in such a manner that the overlying one of the bars is straddled by the legs of the spacer clip. Pivoted retaining means restrain movement of the underlying bar. whereupon pivoted finger means are advanced into engagement beneath the bar to lift the superposed bars into seated position in the spring clip which is ejected from the magazine during the projecting and lifting operation by actuation of a lever mechanism. The crosswisely extending bars thus become tied together at their intersection with the underlying bar resting in the recess of the spring clip and the overlying bar held in position perpendicularly thereto between the legs of the spring clip in contact with the underlying bar.

The tool according to the invention comprises an open ended elongated magazine or channel which has a cross section substantially corresponding to the cross section of the spring clips so that they will be yieldingly retained therein. The spring clip used with the tool comprises a pair of vertically extending spaced leg members which are interconnected at the top by a bridging member to define an inverted generally U- shaped body. Each leg is provided with an open recess for receiving and seating the underlying one of the two superposed bars. The spring clips are provided with guide members for guiding the clips in the channel during their downward movement and a plurality of spring clips may be joined together into a cartridge by means of frangible webs and loaded as a unit into the channel of the tool.

The type of spring clip to which the tool according to the invention is applicable is described in applicants copending application Ser. No. 3,765 filed Jan. 19, 1970 now US. Pat. No. 3,694,988, and in the continuation-in-part application filed concurrently herewith Ser. No. 229,703 filed Feb. 28, 1972. The spring clips are individually forced out from the lower open end of the channel by actuation of a linkage arrangement mechanism which operation also actuates means for restraining the underlying bar against lateral displacement and means for lifting it together with the overlying bar into seated position in the clip when the support member or open foot of thetool is placed over the two intersecting bars.

The bar restraining means and the, lifting means are joumalled in the support member or foot of the tool. The clip ejection means are connected to the lifting means so that they will follow the movement of the lifting means so that they will follow the movement of the lifting means while the underlying bar is restrained against the foot of the tool during the lifting movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tool according to the invention.

FIG. 2 is a similar view showing the rear of the tool.

FIG. 3 is a perspective view drawn to an enlarged scale of the lower part of the tool shown in FIG. 1.

FIG. 4 is a perspective view drawn to an enlarged scale of the lower part of the tool of FIG. 1 showing a spacer clip in the channel in position to be ejected therefrom.

FIG. 5 is a perspective view drawn to an enlarged scale of the upper part of the tool shown in FIG. 1 and a weight acting upon the spacer clip cartridge.

FIG. 6 is a diagrammatic fragmentary sectional view of the lower part of the tool shown in FIG. 1, and showing the position of the spacer clip in a preliminary stage of the elevation of the reinforcing bars.

FIG. 7 is a side view drawn to a similar scale of the lower part of the tool illustrating the reinforcing bars in the process of being lifted.

FIG 8 is a diagrammatic longitudinal sectional view through the tool illustrating the reinforcing bars seated in the spring clip.

FIG. 9 is a side view of the lower part of the tool shown in FIG. 1 illustrating the commencement of the lifting operation of the reinforcing bars, the broken lines showing the position of the parts in their initial stage.

FIG. 10 is a detail view of the rear lower part of the tool with a stop member in contact with the upper reinforcing bars.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The reference numeral 10 indicates the elongated channel or slide chute in which the U-shaped spring clips 11 are slidably inserted (see FIGS. 4, 6 and 9). In order to force the spring clips or cartridge downwards in the channel, they may be loaded by a weight 12 (see FIG. 5). The weight 12 may be provided with a stop 13 to prevent accidental displacement of the spring clips towards the upper portion of the tool when the tool is carried in an non-vertical position. The weight may also be provided with a device at the rear of the upper armate portion 14 of the slide channel whereby the weight 12 may be removed from the slide chute but still connected to the tool.

The tool is provided at its lower end with a boxshaped support member or foot 15, in which two hookshaped members 16, 16' are pivotally mounted which serve as restraining means to hold the underlying one of the bars 17 against lateral displacement with respect to the perpendicularly extending overlying bar 17'. The members 16, 16 may be spring loaded for rapid downward engagement with the reinforcing bar 17. At opposite sides of the foot or support member 15 adjacent the open face of the chute are two arcuately shaped crank plates 18, 18 pivotally shown on member 15 which are provided with fingers 18", 18" adapted to be moved into a position beneath the underlying bar 17 and then to be swung upwardly to lift the superposed bars into the spring clip 11 with the underlying bar received in the recess 11'. The crank arms 18, 18' are journalled at the rear of the channel to the respective legs of the fork-shaped end of a rod 19 which at its other end is pivoted to the lower end of a rod 20 which is slidably mounted in a pluralityof sleeves 2 andgllJlElGS. 2 and The rod adjacent its upper end is provided with handles 21. Expansion springs 22 and 22' are anchored at one end to the rear of the channel 10 and at the other end to the pivot point between the rods 19 and 20 to provide a knee joint.

The springs 22, 22 normally serve to hold the rods in a substantially vertical position. When the handles 21, 21' are depressed, the knee joint between the rods 20 and 19 will bias the rod 19 and swing the crank arms I 18, 18 successively to the positions shown in FIG. 6-8 to engage the underlying bar 17 as shown in FIG. 6 and lift the two bars together after the hook-shaped restraining members 16, 16 have engaged the underlying bar 17 as shown in FIG. 7. After the bars have been seated in position as shown in FIG. 8, the crank arms 18, 18 and the restraining members 16, 16' will be returned to their original position upon release of downward pressure on the handles under the action of the springs 22, 22.

The clip feeding mechanism or clip ejection mechanism comprises two U-shaped brackets 23, 23, each of which is fixed to the interior surface of each crank arm 18, 18'. These brackets thus follow the movement of the crank arms 18 and 18 and are introduced through an opening 23" in the bottom part of the channel 10 into engagement with an intermediate portion of the lowermost clip 11 which is pushed out of the channel during the lifting movement of the crank arms 18, 18' (see FIGS. 6 and 8) and continued movement of the crank arms forces the clip into engagement with the underlying bar 17 which thus is snapped into position in the recess 11' by deflection of the flexible members 11a which spring back after the bar has been received in the recess 11 (see FIG. 8), while the overlying bar is pressed up against a rod engaging surface in the upper portion of the clip. The intersecting bars are thus securely tied together by the spring clip 11 and upon release of the downward pressure on the handles 21, 21, the moving parts are automatically returned to their normal position of rest.

For successful operation of the device, provision must be made to prevent the downward movement of the spacer clips 11, when the moving members are in a position of rest. The spacer clips which are made of synthetic resilient plastic material, and preferably interconnected into the form of a cartridge by means of frangible webs and are provided at opposite sides guide pins 11" extending laterally from hook-shaped flexible members and web-shaped support members 11' which extend laterally from the leg members of the U- shaped spacer clip below the recess 11 thereof. Adjacent the bottom end of the magazine or channel 10 and at opposite sides of the clip discharge opening 23" are mounted funnel shaped retainers 24, 24'. Upon the completion of each successive ejecting operation as shown in FIG. 4, the guide pins 11" and the support members 11" are introduced into the retainers 24, 24'. The guide pins 11" supportedly engage the upper portion of the retainers 24, 24 while the support members 11 guidely engage the interior surfaces thereof.

As the U-shaped ejection brackets 23, 23' force the spacer clip 11 out of the magazine or channel 10, the web like members 11" are flexed rearwardly to permit the spacer clip to be ejected in a horizontal plane, while being sheared from its associated clip in the cartridge which is retained in the magazine and automatically descends downward to a level corresponding to the height of the clip.

For the purpose of permitting the tool according to the invention to be used in a so-called over-edge mode of application of spacer clips to crosswisely intersecting bars, i.e. when the tool is not placed on the deck of the mold form, the rear lower portion of the magazine or channel 10 is provided with a vertically adjustable stop member 25 (see FIG. 10) which engages the overlying bar 17'. Thus member 25 compensates for the support provided by the mold form and serves the same purpose.

The advantage of the method and apparatus according to the present invention over the tool described and claimed in applicants prior US. Pat. No. 3,461,536 is that the present invention permits the tying together and lifting of substantially heavy reinforcing bars having a large cross sectional area without risking lateral displacement of the underlying bar from its position of juncture with the overlying bar. The linkage arrangement according to the invention allows for application of relatively small force to lift heavy reinforcing bars. The tool according to the invention can also be used for so-called over-edge reinforcing", i.e. when the reinforcing bars are arranged at a substantial distance from the mold form and not intended to be raised to a higher level therefrom. Despite the increased field of use of the tool, its weight because of its simplified construction is relatively light.

It will be noted that the tool according to the present invention operates to lift and to guide the reinforcing bars into engagement with the spring clip without the spacer member or spring clip having a cooperating lifting ramp or similar means as shown in applicants US. Pat. No. 3,461,536.

It should be understood that the foregoing description is given by way of example and not by way of limitation. The invention may lend itself to a variety of expressions within the scope of the appended claims.

What is claimed is:

l. The method of lifting and joining two intersecting crosswisely extending superimposed bars into a seated position into a resilient spacer member of inverted generally U-shaped cross section the legs of which have an open recess facing the underlying bar, the axis of which extends transversely to the plane of the bridging portion between the legs, while the spacer member is being ejected from a discharge opening in a magazine in which they are slidably retained, comprising the steps of:

a7 applying a restraining force to the underlying one of the bars to restrain the underlying bar against lateral displacement relative to the overlying bar;

b. applying a lifting force beneath the underlying bar to lift the underlying bar to a desired joining level while continuing to restrain the underlying bar against lateral displacement;

c. forcing a spacer member from the magazine into contact with the intersecting bars during application of the lifting force with the legs of the spacer member in straddled position relative to the overlying bar;

d. continuing the application of the lifting and restraining forces against the spacer member independently of the movement of the spacer member until the underlying bar is received in the recess of the spacer member, and

e. removing the lifting and restraining forces.

2. The method of joining two intersecting bars in a spacer member, as set forth in claim 1, in which the bars are initially supported upon a generally horizontal support surface, the ejection movement of the spacer member being substantially parallel to the support surface, and the lifting movement of the bars being just sufficient to elevate the underlying bar to the level of the entrance to the recess in the spacer member. 

1. The method of lifting and joining two intersecting crosswisely extending superimposed bars into a seated position into a resilient spacer member of inverted generally U-shaped cross section the legs of which have an open recess facing the underlying bar, the axis of which extends transversely to the plane of the bridging portion between the legs, while the spacer member is being ejected from a discharge opening in a magazine in which they are slidably retained, comprising the steps of: a. applying a restraining force to the underlying one of the bars to restrain the underlying bar against lateral displacement relative to the overlying bar; b. applying a lifting force beneath the underlying bar to lift the underlying bar to a desired joining level while continuing to restrain the underlying bar against lateral displacement; c. forcing a spacer member from the magazine into contact with the intersecting bars during application of the lifting force with the legs of the spacer member in straddled position relative to the overlying bar; d. continuing the application of the lifting and restraining forces against the spacer member independently of the movement of the spacer member until the underlying bar is received in the recess of the spacer member, and e. removing the lifting and restraining forces.
 2. The method of joining two intersecting bars in a spacer member, as set forth in claim 1, in which the bars are initially supported upon a generally horizontal support surface, the ejection movement of the spacer member being substantially parallel to the support surface, and the lifting movement of the bars being just sufficient to elevate the underlying bar to the level of the entrance to the recess in the spacer member. 